X5 50i M-Sport - Long Term Reliability?

[Mongojoe]

I bought a CPO X5 50i M-Sport a couple of years ago. It now has 60K on the odometer, and I have another year of extended warranty and maintenance. Really love this vehicle, and only put about 10K per year on it, but am worried about long-term reliability. I've had the "customer care package" service done after a couple of reduced power issues, but not sure if this is a band-aid or a true fix.

Can anyone weigh in on likely maintenance issues and costs for the long haul (out beyond 100K)?

Is the N63tu (M-Sport motor) more or less reliable than the N63?

Thanks!